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http://www.medkaau.com/bssc/Unit%201/Intercollegiate%20Basic%20surgical%20skills%20course.htm
Module one: open surgery The module aims to introduce you to some of the manipulative skills you will require in your career. Complex manoeuvres will need to be assiduously practised, preferably under critical observation, so that you do not acquire bad habits. The aim of this course is to help you acquire good habits early in your career, as it is so much harder to unlearn bad habits later in life. The techniques chosen for this course by all four surgical royal colleges are those which are simple and safe, but we make no claim that these are the only simple and safe techniques. They have been chosen as being simple and proven. An advantage of the British system of training is that you will work for several surgeons in the course of your training, each of whom will show you individually preferred techniques from which you will be able to select those which suit your needs best. However, the techniques taught on this course have been standardised and are recommended for their simplicity and safety. Handling instruments Knots Handling sutures Handling tissues Handling bowel Abdominal incision and closure Handling vessels Handling instruments In order to achieve maximum potential from any surgical instrument, it will need to be handled correctly and carefully. The basic principles of all instrument handling include: safety; economy of movement; relaxed handling; and avoidance of awkward movements. We shall demonstrate the handling of scalpels, scissors, dissecting forceps, haemostats and needle holders. Take every opportunity to practise correct handling using the whole range of surgical instruments. The scalpel View the video clip Handle with great care as the blades are very sharp. Practise attaching and detaching the blade using a haemostat. Never handle the blade directly. For making a routine skin incision hold the scalpel in a similar manner to a table knife, with your index finger guiding the blade. Keep the knife horizontal and draw the whole length of the sharp blade, not just the point, over the tissues (Figure 2).  Figure 2 For finer work the scalpel may be held like a pen, often steadying the hand by using the little finger as a fulcrum (Figure 3). Figure 3 Always pass the scalpel in a kidney dish. Never pass the scalpel point first across the table. Scissors View the video clip There are two basic types of scissors, one for soft tissues and one for firmer tissues such as sutures. Insert the thumb and ring finger into the rings (or bows) of the scissors so that just the distal phalanges are within the rings (Figure 4). Any further advancement of the fingers will lead to clumsy handling and difficulty in extricating the fingers at speed. Figure 4 Use the index finger to steady the scissors by placing it over the joint. When cutting tissues or sutures, especially at depth, it often helps to steady the scissors over the index finger of the other hand (Figure 5). Figure 5 Cut with the tips of the scissors for accuracy rather than using the crutch which will run the risk of damaging tissues beyond the item being divided and will also diminish accuracy. Dissecting forceps View the video clip Hold gently between thumb and fingers, the middle finger playing the pivotal role (Figure 6). Figure 6 Two main types of forceps are available: toothed for tougher tissue such as fascia or skin, and non-toothed (atraumatic) for delicate tissues such as bowel and vessels. Never crush tissues with the forceps but use them to hold or manipulate tissues with great care and gentleness. Haemostats (artery forceps) View the video clip Hold haemostats in a similar manner to scissors. Place on vessels using the tips of the jaws (the grip lessens towards the joint of the instrument). Secure position using the ratchet lock. Learn to release the haemostat using either hand. For the right hand, hold the forceps as normally, then gently further compress the handles and separate them in a plane at right angles to the plane of action of the joint. Control the forceps during this manoeuvre to prevent them from springing open in an uncontrolled manner. For the left hand, hold the forceps with the thumb and index finger grasping the distal ring and the ring finger resting on the under surface of the near ring (Figure 7). Gently compress the handles and separate them again at right angles to the plane of action, taking care to control the forceps as you do so. Figure 7 Needle holder View the video clip Grasp the needle holders in a similar manner to scissors. Hold the needle in the tip of the jaws about two-thirds of the way along its circumference (Figure 8), never at its very delicate point and never too near the swaged eye (see Appendix A). Figure 8 Select the needle holder carefully. For delicate, fine suturing use a fine short-handled needle holder and an appropriate needle. Suturing at depth requires a long-handled needle holder. Most needle holders incorporate a ratchet lock but some, e.g. Gilles, do not. Practise using different forms of needle holder to decide which is most applicable for your use. There are a wide variety of needle and suture materials available and their use will depend on the tissues being sutured and the nature of the anastomosis. For a full description of needles and suture materials see Appendix A and Appendix B. View the video clip on types of needle Exercise Practise the correct handling of each of the instruments (scalpels, scissors, dissecting forceps, haemostats and needle holders) as demonstrated. Knots Knot tying is one of the most fundamental techniques in surgery and is often performed very badly. Take time to perfect your knot tying technique as this will stand you in good stead for the rest of your career. Practise regularly with spare lengths of suture material. General principles of knot tying include: The knot must be firm and unable to slip. The knot must be as small as possible to minimise foreign material. During tying do not 'saw' the material as this will weaken the thread. Do not damage the suture material by grasping it with artery forceps or needle holders except at the free end when using an instrument tie. Avoid excess tension during tying as this could damage the structure being ligated or even cause breakage of the suture material. Avoid tearing the tissue being ligated by controlling tension at 'bedding down' of the knot very carefully using the index finger or thumb as appropriate. You will be taught and asked to demonstrate the following: The one-handed reef knot; an instrument tied reef knot; the surgeon's knot; a slip knot (the granny knot); and tying at depth. The standard knot used in routine surgery is the reef knot with a third throw for security. This is usually tied using the one-handed method and this technique should be mastered and practised regularly during the course. The principles of the reef knot are the alternating ties of the 'index finger' knot and the 'middle finger' knot at the same time as the hands cross over for each throw. View the reef knot principle video clip The one-handed reef knot technique View the video clip Exercise Hold the end of the short end of the suture between the thumb and middle finger of the left hand with the loop over the extended index finger (Figure 9a). Hold the remainder of the suture material with the right hand. Figure 9a Bring the remainder of the suture material in the right hand over the left index finger by moving the right hand away from the operator (Figure 9b). Figure 9b Use the distal phalanx of the left index finger to pass under the thread held in the left hand in preparation for pulling it through the loop (Figure 9c). Figure 9c Pull the thread through grasping it between left index and middle fingers and complete the throw by drawing the left hand towards the operator and the right hand away from the operator (Figure 9d). Figure 9d Continue to hold the short end of the suture in the left hand between thumb and index finger looping the thread around the other three fingers (Figure 9e). Figure 9e Bring the strand held in the right hand across the middle finger towards the operator to cross the left-handed thread (Figure 9f). Figure 9f Use the distal phalanx of the left middle finger to bring the left-handed strand under the right-handed strand (Figure 9g). Figure 9g Bring the strand through holding it between the middle and the ring finger and then tighten by drawing the right hand towards the operator and the left hand away from the operator (Figure 9h). Figure 9h On completion the classical pattern of the reef knot can be clearly seen (Figure 9i and 9j). Figure 9i Figure 9j For security another index finger throw is usually applied. The instrument tie View the video clip Exercise Loop the long end of the suture around the instrument, the instrument being placed over the thread (Figure 10a). v Figure 10a Grasp the short end of the suture within the jaws of the instrument (Figure 10b). Figure 10b Complete the first hitch (Figure 10c). Figure 10c Now form a loop around the instrument, this time the instrument being placed under the thread (Figure 10d). Figure 10d Grasp the short end within the jaws of the instrument (figure 10e). Figure 10e Pull through to complete the classical reef knot (Figure 10f). v Figure 10f The surgeon's knot View the video clip Exercise A single throw is placed using a one-handed or two handed technique (Figure 11a). Figure 11a A further throw in the same manner is placed (Figure 11b). Figure 11b The double throw is tightened in a conventional manner (Figure 11c). Figure 11c A further throw is now fashioned in the same manner as for a reef knot but not tightened (Figure 11d). Figure 11d A similar throw is again fashioned producing a double throw as before (Figure 11e). Figure 11e The double throw is now tightened (Figure 11f). Figure 11f The result may not look very pretty but it is very secure as long as the final throw is tightened as horizontally as possible (Figure 11g). Figure 11g The slip knot View the video clip Exercise This should be used with care as it is not secure. Two similar throws are placed consecutively and then snugged down (Figures 12a and 12b). Figure 12a Figure 12b This does not produce the classical picture of a reef knot but it does slip and can be used to ensure the right tension of the knot (Figure 12c). Figure 12c A formal reef knot needs to be tied now in order to give the knot security (Figure 12d). Figure 12d Tying at depth View the video clip Exercise The thread should be placed around the object to be ligated with the right index finger (Figure 13a) or using an instrument such as a haemostat. Figure 13a Fashion a classical throw for a reef knot on the surface (Figure 13b). Figure 13b Advance the knot down into the cavity using the right index finger (Figure 13c). Figure 13c Snug the knot down using tension on the long strand against the index finger of the right hand, ensuring no tension exists on the structure being ligated. Fashion a further throw on the surface in the manner of a reef knot (Figure 13d). Figure 13d Advance into the cavity and snug down with the right index finger as before (Figure 13e). Figure 13e Handling sutures View the video on sutures and suture handling Basic principles Attempt to remove all elements of tension from any anastomosis. Insert the needle at right angles to the tissue and gently advance through the tissue avoiding shearing forces. As a rough rule of thumb, the distance from the edge of the wound should correspond to the thickness of the tissue and successive sutures should be placed at twice this distance apart, i.e. approximately double the depth of the tissue sutured (Figure 14). Figure 14 All sutures should be placed at right angles to the line of the wound at the same distance from the wound edge and the same distance apart in order for tension to be equal down the wound length. The only situation where this should not apply is when suturing fascia or aponeuroses when the sutures should be placed at varying distances from the wound edge in order to prevent the fibres parting (Figures 15a and 15b). Figure 15a Figure 15b For long wounds being closed with interrupted sutures, it is often advisable to start in the middle and to keep on halving the wound. No suture should be tied under too much tension or the subsequent oedema of the wound may cause the sutures to cut out or to develop ischaemia of the wound edge and delayed healing. In most cases it is advisable to only go through one edge of the tissues at a time but, if the edges lie in very close proximity and accuracy can be ensured, it is permissible to go through both edges at the same time. For elliptical wounds following lesion excision, the edges of the wound may be undermined to help closure. However, the length of the wound will need to be approximately three times the width of the wound if closure is to be safe and not under too much tension. Skin hooks may be useful to display the wound. Forms of suturing You will be taught and asked to demonstrate the following types of suturing: interrupted sutures; continuous sutures (including the art of 'following'); mattress sutures; subcuticular sutures; and inverting and everting techniques. Interrupted sutures (Figure 16) View the video clip Figure 16 Exercise Place carefully at right angles to the wound edges. Tie a careful reef knot and lay to one side of the wound. Cut suture ends about 0.5cm long to allow enough length for grasping when removing. When removing sutures, cut flush with the tissue surface so that the exposed length of the suture, which is potentially infected, does not have to pass through the tissues (Figures 17a and 17b). Figure 17a Figure 17b Continuous sutures (Figure 18) View the video clip Figure 18 Exercise Place a single suture and ligate but only cut the short end of the suture. Continue to place sutures along the length of the wound keeping tension by means of an assistant 'following' by holding the suture at the same tension as it is when handed to them. Take care not to 'purse string' the wound by too much tension. Take care not to produce too much tension by using too little suture length. Secure the suture at the end of the anastomosis by a further reef knot. Mattress sutures View the video clip Exercise Mattress sutures may be either vertical (Figures 19a and 20a) or horizontal (Figures 19b and 20b). Figure 19a Figure 19b They may be useful for ensuring either eversion (Figures 19a and b) or inversion (Figures 20a and b) of a wound edge. Figure 20a Figure 20b Subcuticular sutures (Figure 21) View the video clip Figure 21 Exercise This technique may be used with absorbable or non-absorbable sutures. For non-absorbable sutures the ends may be secured by means of beads, etc. For absorbable sutures the ends may secured by means of buried knots. Small bites are taken of the subcuticular tissues on alternate sides of the wound and these are then pulled carefully together. View the 'art of assisting' video clip Skin lesion biopsy View the video clip Exercise Make an elliptical incision around the lesion. Dissect the lesion out taking care not to disrupt or burst it. Remove the lesion (always send for histological examination). Undermine the skin edges if necessary. Ensure that not too much tension exists for closure. Length of the wound should be approximately three times the width of the wound. If any tension exists, it is easier to start in the corners and work towards the centre. If no tension exists, the wound may be closed by starting in the centre and then halving the remaining wound. Close the wound with interrupted sutures. Handling tissues Haemostasis View the video clip Two methods of securing haemostasis by ligation will be demonstrated using vessels in small bowel mesentery. Exercise - single vessel ligation Carefully dissect out a single vessel in the mesentery by dividing the peritoneum over it and isolating a length of vessel on its own. If possible do not go right through the peritoneum on the other side of the mesentery. Pass ligature threads under the vessel by means of haemostats and ligate at either end of the isolated length of vessel. Divide the vessel between the two ligatures and cut the suture material of the knots. Exercise - pedicle ligation Isolate a pedicle or leash of vessels and place a haemostat at either end. Divide the vessels between the haemostats. Ligate the vessels in each haemostat with a three-throw reef knot. Dissection (if time and specimen allow) Lymph node biopsy is commonly required for histological examination. View the video clip Exercise For this exercise the nodes in small bowel mesentery are to be used. Carefully divide the peritoneum over the node. Dissect the node with care, avoiding any crushing of the node or damage to the underlying tissues. Minimal handling of the node is desirable. Each node will have feeding vessels which in normal circumstances would need to be dealt with by diathermy or ligation. Handling bowel Bowel anastomosis The basic principles of bowel anastomosis will be demonstrated using a small bowel anastomosis. The essentials for any anastomosis are: no tension; good blood supply (pulsating mesenteric vessels); accurate apposition; and impeccable and accurate suture technique. Although not the only safe suture method for small bowel anastomosis, the technique to be demonstrated on this course will be the single layer extramucosal suture (Figure 22). Figure 22 The basic exercise will be performed as an end-to-end anastomosis on mobile small bowel that can be turned to reveal the posterior wall. Each participant will have an opportunity to perform a complete anastomosis and also assist their partner in their anastomosis. Two sessions on bowel anastomosis are included in the course and, for participants who perform well, the techniques of end-to-side anastomosis on non-mobile bowel will also be demonstrated. A continuous technique is also permissible, taking care not to purse string the anastomosis. End-to-end extramucosal anastomosis View the video clip on end-to-end anastomosis with interrupted suture View the video clip on end-to-end anastomosis with continuous suture Exercise Assume resection of a lesion. Line up the ends of the bowel. In operative circumstances non-crushing bowel clamps may be used to prevent spillage, etc. Use 3/0 absorbable suture material with an atraumatic round bodied needle. Each suture should perforate the bowel from the serosal surface, penetrating the muscle layer and submucosa and emerging between the mucosa and submucosa (Figure 22). It is essential to include the submucosa as this is the strongest layer of the bowel wall. Insert stay sutures at the mesenteric and antimesenteric borders; do not ligate them but place in haemostats. Starting from the mesenteric aspect, place interrupted sutures along the anterior wall of the bowel at approximately 0.5cm apart and tie as they are placed. On completion, tie both stay sutures, but do not cut and replace in haemostats. Pass antimesenteric stay suture under bowel to emerge in mesenteric defect and, at the same time, draw mesenteric stay suture in the opposite direction which will reverse the bowel and the posterior wall will now lie anteriorly. Suture the new front wall in a similar manner using interrupted extramucosal sutures taking care to ensure the angles are adequately sutured. On completion, return the stay sutures to their original position, then cut them and inspect the anastomosis. In normal situations the mesenteric defect must be closed, taking care not to damage the mesenteric vessels. In the exercise situation, cut out the anastomosis and then open it up and inspect from the inside as well as the outside. Very little suture material should appear within the lumen if the extramucosal suture technique has been adequately inserted. If a continuous technique is to be employed, place a stay suture at the antimesenteric border. Do not tie but place in a haemostat. In the same manner, place a stay suture at the mesenteric border using a full length of suture, ligate it and place the short end in a haemostat. Take the other end and use it to place a continuous suture across the anterior wall of the anastomosis until the antimesenteric stay is reached. Once again, an extramucosal suture technique is used. Care must be taken not to purse string the anastomosis so the careful attention of an assistant is essential. The antimesenteric stay can now be tied but not cut. The bowel is now reversed in the same way as before, passing the needle and suture under the partially fashioned anastomosis. On reversal of the bowel, either continue on with the same suture until the mesenteric stay is reached and tied to it, or use a double needle suture at the outset for the mesenteric stay suture, and the new front wall can then be sutured from the mesenteric aspect towards the antimesenteric aspect as before, using the other needle. End-to-side anastomosis on immobile bowel View the video clip Exercise Use an end-to-side small bowel anastomosis to demonstrate this technique. In this technique the posterior wall is sutured first using a vertical mattress suture technique (Figure 23a). Each suture should perforate the full thickness of the bowel wall from within the lumen and then traverse the other portion of bowel full thickness from outside to inside. The suture should then return taking a small segment of the mucosa on both sides. A reef knot should then be tied on the lumen surface. Figure 23a The anastomosis should be started with the corner stay sutures inserted in an extramucosal fashion but it is best not to tie them until later. It is advisable to insert a stay suture in the middle of both anterior walls as this will facilitate the view of the posterior walls that are about to be sutured. Alternatively, tissue holders such as Babcocks can be used in the same manner. Insert all the posterior wall sutures as above, tying as you go. Now tie the stay sutures which are the first sutures of the anterior layer and replace in the haemostats. The mid-anterior wall stay sutures can now be released. Then insert all the anterior sutures in an extramucosal manner as before (Figure 23b). Figure 23b Once again excise the anastomosis and open it up for inspection. In this case all the posterior sutures should be easily apparent within the lumen but the anterior sutures should be hardly visible. The Aberdeen knot View the video clip Exercise This knot is useful when, having finished a continuous suture, you are left with a loop and a free end (Figure 24a). Figure 24a Display the loop between the index finger and thumb of your left hand making it as small as possible by pulling on the other end of the thread with your right hand (Figure 24b). Figure 24b Grasp the free end between the index finger and thumb of the left hand through the loop (Figure 24c) and by pulling it through and releasing the right hand thread, the old loop is eliminated (Figure 24d). Figure 24c Figure 24d Once again the new loop is made as small as possible by pulling on the right-hand thread, and the whole process is repeated using a type of 'sea saw' movement (Figure 24e). Figure 24e The whole process is then repeated about 6 - 7 times (Figure 24f). Figure 24f Finally, pass the free end through the loop (Figure 24g) and tighten down (Figure 24h). The thread can now be cut. Figure 24g Figure 24h Abdominal incision and closure View the video clip Exercise You will be provided with a simulator representing the abdominal wall. It will consist of two layers of material simulating the skin and linea alba of the abdominal wall. They will be stretched over an inflated balloon which is to represent loops of bowel within the peritoneal cavity. The aim of the exercise is to enter the peritoneal cavity without damaging the inflated balloon, and then to close the abdominal wall again without bursting the balloon. Make a midline incision in the simulated abdominal wall skin (Figure 25a). Figure 25a Expose the simulated linea alba and lift up using haemostats (Figure 25b). Figure 25b Incise the linea alba carefully ensuring no damage to the underlying balloon (Figure 25c). Figure 25c Enlarge the incision using scissors until the incision is adequate for whatever procedure is intended (Figure 25d). Figure 25d Proceed to close the incision by inserting a non-absorbable suture at one end of the incision, ligating the ends with the knot on the inside. As most suture materials used for this closure are monofilament, several throws are required, laying each one formally as a reef knot. Many surgeons will place at least one of these throws as a surgeon's knot. Currently many surgeons are now using a blunt needle (Figure 25e) for this procedure in order to minimise the risk of needle stick injuries. Figure 25e The suture length should be four times the length of the incision in order to ensure that there is enough suture material for 1 cm bites placed less than 1 cm apart. The suture should not be pulled too tight as this could result in tissue necrosis. If the suture length is not adequate, a further suture can be inserted starting at the other end of the incision. Close the entire wound always ensuring that no loop of bowel or tissue is caught up by the suture material (Figure 25f). Figure 25f Tie the suture material at the end of the closure, either by several conventional throws or by using an Aberdeen knot. If a loop suture is used, one of the strands can be cut close to the needle. The other end, still on the needle, can then be passed again through the tissues. Next the two ends can be ligated with several throws of a reef knot and the knot buried. The knot should be buried by cutting off the short end or loop and then passing the needle through the tissues. Pull the knot deep into the closure and then cut the suture off flush (Figure 25g). The complete closure should then be inspected. Figure 25g A simplified model for this exercise can be provided by modifying a 'lunch box' as shown in Figure 25h (courtesy of Professor E Guiney). Figure 25h Handling vessels View the video clip Vascular anastomoses Vessels need to be handled in a very different manner from bowel. Extreme gentleness in handling is required and whenever possible a vessel should be manipulated by grasping the peri-arterial or adventitial tissues only. When direct manipulation is unavoidable, arterial wall should never be grasped between forceps for fear of injury to the intima or even a full thickness tear. Two methods for atraumatic handling of vessel walls may be used, either using the tips of closed dissecting forceps to gently open the arteriotomy (Figure 26a) or using the suture material to be used for the anastomosis to retract the arterial wall (Figure 26b). Figure 26a Figure 26b When suturing arterial wall it is advisable for the needle to pass from inside to out (i.e. from intima to adventitia) to fix any atherosclerotic plaques and prevent the formation of intimal flaps which may lead to dissection, embolisation or thrombosis. Non-absorbable, monofilament suture material that moves smoothly through the vessel wall is required. These suture materials require a careful knot technique and several throws to prevent the knot unravelling (most vascular surgeons recommend six or seven throws). Do not damage the suture material by gripping it with dissecting forceps, the needle holder or a haemostat as this can lead to fracture. For the same reason, all knots need to be hand-tied and the haemostat jaws should be covered with rubber (rubber shod). Fine, accurate, watertight sutures need to be inserted at even tension when suturing vessels. Always insert the needle at right angles to the wall and pass it through the wall with several short 'pushes' which allow the needle to travel on the arc of its own circle, thus not splitting or tearing the delicate wall. The finer the vessel, the finer the sutures required and the smaller the bites taken. Therefore, aortic sutures need large bites while femoral sutures require fine bites. Distal anastomoses are often facilitated by operating 'loupes' - glasses which magnify the image between two and four times. A smooth internal suture line is essential or else platelet aggregates will collect and compromise the anastomosis. The suture line needs to be everted to result in good intimal apposition, unlike a bowel anastomosis in which the suture line tends to be inverted. Technique of transverse arteriotomy Once an artery has been dissected free and inflow and outflow controlled, arteriotomy is performed to gain access to the lumen. For simple procedures such as embolectomy, a transverse arteriotomy is simplest and can be closed primarily. When more complex procedures are anticipated (e.g. endarterectomy or a graft anastomosis) a longitudinal arteriotomy provides the necessary flexibility. In all but the largest calibre of vessels, longitudinal incisions require closure with a patch to prevent stenosis. Primary closure of a transverse arteriotomy results in minimal stenosis of the vessel lumen (Figure 27a) whereas primary closure of a longitudinal incision produces a long stenosis which may reduce flow and promote thrombosis (Figure 27b). Figure 27a Figure 27b Exercise Use a sharp, fine-pointed blade (e.g. a number 11 blade) and approach the vessel at right angles to the site of the incision. In most circumstances, commence your incision on the uppermost surface of the vessel. With the blade facing away from you, use a short stabbing motion to pierce the anterior wall. Beware of the point of the scalpel entering the vessel too deeply and penetrating the opposing wall. Once the blade has entered the vessel lumen, lift it up and away to make a small opening in the wall without damaging the inside of the artery (Figure 28a). Figure 28a Complete the arteriotomy in a controlled manner using appropriately angled Pott's artery scissors (Figure 28b). Lift the blade within the lumen away from the posterior wall to avoid damaging the inside of the vessel. Aim to open the vessel around 1/3 to 1/2 of its circumference, depending on how much access is required. Figure 28b Inspect the lumen of the artery using one or more of the atraumatic techniques described above. Primary closure of a transverse arteriotomy For primary closure of an arteriotomy, use two appropriately sized, double-ended arterial sutures. Two suture lengths are used to allow suturing to begin in both corners of the arterial incision in order to avoid placing the last stitch at the corner of the arteriotomy, which can be difficult. By definition, not all of the sutures can pass through both arterial walls from inside to out. Plan the placement of your stitches whenever possible so that 'intima to adventitia' suturing occurs on the 'downstream' side of the incision (as dissection is most likely on this side once blood flow is restored). Exercise Commence at either end of your arteriotomy and pass both needles from inside to out (Figure 29). Tie the suture and secure in a rubber shod haemostat. Figure 29 Use your other suture in a similar manner at the opposite extreme of the arteriotomy and then continue suturing using fine, evenly spaced stitches until you reach the apex of the vessel. At this point, secure the apical thread in a rubber shod haemostat and begin stitching with your first placed suture (Figure 30). When the sutures come close at the apex, the last thread can be left loose to facilitate suturing under direct vision as much as possible. Figure 30 Tie the knot at the apex of the vessel after flushing inflow and outflow vessels to get rid of air and thrombus. Vein patch graft View the video clip A vein patch is the safest way to close an arteriotomy if there is the slightest suspicion that direct closure will produce narrowing. Exercise Make an elliptical arteriotomy about 3cm long in the vessel provided. Then cut one end of an elliptical patch in the simulated vein patch or prosthetic material provided. Leave the other end of the patch long and unshaped at this stage. The redundant portion can be used to handle the patch without damaging intima which will be in contact with flowing blood in vivo. Using a 5/0 prolene suture, insert an initial stitch from outside to inside at the shaped end of the patch and then pass it inside to outside through the apex of your arteriotomy (Figure 31). Tie the suture and anchor one end in a rubber shod haemostat. Figure 31 Take the free end of the suture and work down the far side of the arteriotomy. Insert continuous stitches using fine bites while holding the redundant portion of the patch with your forceps (Figure 32). It is inadvisable to suture both vein patch and arterial walls with a single traverse of the needle unless you are experienced. Suture the two walls separately. Figure 32 When you near the heel of the arteriotomy, cut the patch to length transversely and then shape into an ellipse. Continue around the apex and place two or three sutures along the proximal wall. Now move back to your original suture and continue along the proximal wall until you meet the original suture. Flush inflow and outflow vessel before tying the two sutures at this point. At the end of the procedure cut out the anastomosis and observe from within the lumen. There should be no roughness and no irregularity or inversion of the suture line. |
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